.app{
	width: 100%;
	height: 100vh;
	background-color: #ffffff;
	position: relative;
	display: flex;
	justify-content: center;
	align-items: center;
}
.btn30{
	height: 42px;
	position: relative;
	cursor: pointer;
	display: flex;
	overflow: hidden;
}
.btn-text30{
	width: 36px;
	height: 42px;
	line-height: 42px;
	text-align: center;
	display: block;
	background-color: #457356;
	color: #ffffff;
	font-size: 16px;
	font-weight: 700;
	position: relative;
}
.btn-text30:after{
	width: 36px;
	height: 42px;
	position: absolute;
	background-color: #3185fa;
	color: #ffffff;
	z-index: 99;
	transition: 0.3s ease-in-out;
}
.btn-text30:nth-of-type(1):after{
	content: '学';
	top: -42px;
	left: 0;
}
.btn-text30:nth-of-type(2):after{
	content: '无';
	top: 42px;
	left: 0px;
}
.btn-text30:nth-of-type(3):after{
	content: '止';
	top: -42px;
	left: 0;
}
.btn-text30:nth-of-type(4):after{
	content: '境';
	top: 42px;
	left: 0px;
}
.btn30:hover .btn-text30:after{
	top: 0;
}